- Administration of any topical ocular (prescription or over the counter including artificial tears) or systemic medication including herbal product or fish oil preparations within 14 days before the first dose of study drug. Vitamins and mineral supplements not containing other substances are allowed until 96 hours before each dose if considered by the Investigator unlikely to interfere with the study results. Paracetamol at doses of at most 2 grams per day and ibuprofen at doses of at most 1200 mg per day for no more than 3 consecutive days or 6 non-consecutive days are allowed. Oral, injectable and implantable hormonal contraceptives are allowed without restrictions for female subjects. Longer exclusion periods apply for: